Cutting or grinding machine

ABSTRACT

A ultrasonic cutting or grinding machine is composed of an exchangeable cutting or grinding rod, a chuck holding the cutting or grinding rod at a middle portion or rear end thereof, a motor having a rotatable rod, and a transmission rod connecting the chuck and the rotatable rod of the motor, in which the cutting or grinding rod has a ultrasonic transducer on its rod in an area between a front end of the rod and a portion in contact with the chuck.

FIELD OF THE INVENTION

This invention relates to a cutting or grinding machine equipped with a ultrasonic transducer which is favorably employable for processing an article of rigid material such as inorganic glass, silicon, silicon nitride, or hard metal. The invention further relates to a cutting or grinding rod favorably employable for processing an article of rigid material.

BACKGROUND OF THE INVENTION

The cutting or grinding machine equipped with a ultrasonic transducer, that is, a ultrasonic cutting or grinding machine, is well known.

FIG. 1 illustrates a known ultrasonic cutting machine using a grind stone as a cutting means. The ultrasonic cutting machine 10 comprises:

(1) a rotatable cutting unit composed of:

a cutting rod 11 which is composed of a holder rod 11 a and a grind stone 11 b;

a horn 12 attached to the top of the holder rod 11 a;

a booster 13 attached to the top of the horn 12;

a ultrasonic transducer (i.e., ultrasonic vibrator) 14 attached to the top of the booster 13; and

a slip ring 15 attached to the top of the ultrasonic transducer 14;

(2) a driving unit composed of:

an AC spindle motor 16 having a rotatable rod 16 a and a servo unit 16 b; and

(3) a housing composed of:

a cylindrical wall 17, a bearing unit 18 placed between the rotatable cutting unit and the cylindrical wall 17;

and

(4) a ultrasonic wave generator 19 equipped with a carbon brush 20 in which the combination of the slip ring 15 and the carbon brush 20 supplies a ultrasonic energy to the ultrasonic transducer 14.

The ultrasonic cutting machine 10 of FIG. 1 is operated for cutting a workpiece (not shown) in the following manner:

The AC spindle motor 16 is activated under control of the servo unit 16 b to rotate the rotatable rod 16 a. The cylindrical cutting unit rotates synchronously with the rotation of the rotatable rod 16 a under the condition that the cylindrical cutting unit is enclosed and held with the bearing 18. Simultaneously, a ultrasonic generator 19 generates and transmits a ultrasonic wave to the ultrasonic transducer 14. The ultrasonic vibration produced in the ultrasonic transducer 14 is then transmitted to the grind stone 11 b through the booster 13, horn 12, and a holder rod 11 a.

The present inventor studied the known ultrasonic cutting machine and has found that the known ultrasonic cutting machine of FIG. 1 has problems in that not a small portion of the ultrasonic energy generated in the ultrasonic generator 19 is absorbed by the cylindrical wall 17 through the bearing 18 in the course of its transmission toward the grind stone 11 b. In order to compensate the loss of the ultrasonic power, it is required to use a ultrasonic generator having a large capacity. Moreover, since the ultrasonic energy escaping through the bearing 18 vibrates the bearing 18, the power of the bearing gripping the rotating cylinder unit is weakened, and sometimes the vibration causes breakage of the bearing 18 (holding or gripping means).

SUMMARY OF THE INVENTION

Accordingly, it is an object of the invention to provide a ultrasonic cutting or grinding machine that can utilize a generated ultrasonic energy efficiently.

It is another object of the invention to provide a ultrasonic cutting or grinding machine which can be constructed in a relative small size.

It is a further object of the invention to provide a ultrasonic cutting or grinding machine that is almost free from decrease of holding power provided by means for holding a cutting or grinding tool.

The present invention resides in a cutting or grinding machine comprising an exchangeable cutting or grinding rod, a chuck gripping the cutting or grinding rod by a middle portion or rear end thereof, a motor having a rotatable rod, and a transmission rod connecting the chuck and the rotatable rod of the motor, wherein the cutting or grinding rod has a ultrasonic transducer thereon in an area between a front end of the rod and a Portion in contact with the chuck.

The invention further resides in a cutting or grinding rod having a ultrasonic transducer thereon.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrates a conventional cutting machine equipped with a ultrasonic transducer.

FIG. 2 illustrates an example of the cutting or grinding machine according to the invention.

FIG. 3 illustrates a cutting rod according to the invention.

FIG. 4 is a schematic view of another example of the cutting or grinding rod according to the invention.

FIG. 5 is a section of the cutting or grinding rod of FIG. 4 taken along the line A-A.

FIG. 6 is a schematic view of a further example of the cutting or grinding rod according to the invention.

FIG. 7 is a section of the cutting or grinding rod of FIG. 6 taken along the line A-A.

Each of FIGS. 8 and 9 shows a section of a still further example of the cutting or grinding rod according to the invention.

FIG. 10 is a schematic view of a still further example of the cutting or grinding rod according to the invention.

FIG. 11 is a top view of a still further example of the cutting or grinding rod according to the invention.

FIG. 12 is a section of the cutting or grinding rod of FIG. 11 taken along the line A-A.

FIG. 13 is a schematic view of a still further example of the cutting rod according to the invention.

FIG. 14 illustrates another example of the cutting or grinding machine according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the cutting or grinding rods employable for manufacturing the cutting or grinding machine of the invention are described below.

(1) The cutting or grinding rod has the ultrasonic transducer therearound in the form of a continuous or divided ring.

(2) The cutting or grinding rod has a flange on which the ultrasonic transducer in the form of a continuous or divided ring is arranged.

(3) The cutting or grinding rod is a rod having a grind stone at its front end.

(4) The cutting or grinding rod is a drill.

(5) The cutting or grinding rod is an end mill.

(6) The cutting or grinding rod comprises a holder rod and a throw-away tip attached to the holder rod.

(7) The cutting or grinding rod comprises a holder rod and a throw-away tip attached to the holder rod, and the ultrasonic transducer is placed on the throw-away tip.

The present invention is further described by referring to the figures shown in the attached drawings.

FIG. 2 illustrates an example of the cutting or grinding machine according to the invention.

In FIG. 2, the cutting or grinding machine 20 of the invention comprises an exchangeable cutting or grinding rod 21, a chuck 22 gripping the cutting or grinding rod 21 by its middle portion or its rear ends, a motor 23 having a rotatable rod 24, and a transmission rod 25 connecting the chuck 22 and the rotatable rod 24 of the motor 23. The cutting or grinding rod 21 has a ultrasonic transducer 26 thereon in an area between a front end 27 of the rod 21 and a portion 28 in contact with the chuck 22. The transmission rod 25 is held with a bearing 29 so that the rod 25 can rotate stably its axis. Around the transmission rod 25, there is provided a slip ring 31 to Which a ultrasonic energy is transmitted from a ultrasonic generator 31. A rotor (not shown) provided around the transmission rod 25 receives the ultrasonic energy from the slip ring 30 and then transmits it to the ultrasonic transducer through an electric line (not shown) arranged along the transmission rod 25. There is provided a workpiece 32 below the cutting or grinding rod 21. The workpiece is placed on a table 33.

The cutting or grinding procedure can be carried out in the following manner using the cutting or grinding machine of FIG. 2 according to the invention.

When the motor 23 is activated and a rotation energy is applied to the rotatable rod 24, the transmission rod 25 connected to the rotatable rod 24 rotates synchronously within the bearing 29. The chuck 22 provided to the bottom end (i.e., front end) of the transmission rod 25 also rotates synchronously together with the cutting or grinding rod 21 which is firmly gripped and held with the chuck 22. Simultaneously, the ultrasonic generator 31 is activated to generate and transmit a ultrasonic energy to the slip ring 30. The ultrasonic energy received by the slip ring 30 is then transmitted to the ultrasonic transducer 26. The ultrasonic transducer 26 generates ultrasonic vibration along the length of the cutting or grinding rod 21. The ultrasonic vibration generated in the ultrasonic transducer 26 is transmitted directly and almost predominantly to the front end (i.e., bottom end) of the rod 21. Only a small amount of the generated ultrasonic vibration is transmitted to the position 28 in contact with the chuck 22. Accordingly, the generated ultrasonic vibration is very efficiently utilized to vibrate the cutting or grinding rod 21. Further, since only a small amount of the ultrasonic vibration is transmitted to the chuck 22, the holding power provided to the cutting or grinding rod 21 by the chuck 22 hardly decreases. Furthermore, damage of the chuck due to the transmitted ultrasonic vibration hardly occurs.

FIG. 3 illustrates a cutting rod according to the invention.

The cutting rod 21 of FIG. 3 is an end mill, and the end mill 21 has a ultrasonic transducer 26 therearound in the middle portion.

FIG. 4 is a schematic view of another example of the cutting or grinding rod according to the invention, and FIG. 5 is a section of the cutting or grinding rod of FIG. 4 taken along the line A-A.

The cutting or grinding rod 41 of FIG. 4 is a grinding rod having a grind stone at the front end (i.e., at the bottom) of the rod. The grinding rod 41 has a flange 41 a. In FIG. 4, a ultrasonic transducer 46 is provided around the rod 41. The ultrasonic transducer can be provided around the flange 41 a. Otherwise, one ultrasonic transducer is provided around the grinding rod 41 and another ultrasonic transducer is provided around the flange 41 a.

FIG. 6 is a schematic view of an example of the cutting or grinding rod according to the invention, and FIG. 7 is a section of the cutting or grinding rod of FIG. 6 taken along the line A-A.

In FIGS. 6 and 7, the cutting or grinding rod 60 is a grinding rod 61 having a grind stone at its bottom end. The grinding rod 61 is in the form of a three-armed tuning fork having a flange portion 61 a. On the flange portion 61 a, there is placed a ultrasonic transducer 66 in the form of ring. The grinding rod 61 is gripped with a chuck by its upper portion.

The grinding rod 60 can be made of a rod portion 61 b and a flange portion 61 a, and one of these portion such as the flange portion 61 a can has the ultrasonic transducer 66, as is shown in FIG. 8. Otherwise, the ultrasonic transducer 66 can be placed not only on the flange portion 61 a but also on the rod portion 61 b, as is shown in FIG. 9.

The ultrasonic transducer can be in the form of a ring as shown in FIGS. 3 to 9. Otherwise, the ultrasonic transducer can be in the form of a divided ring, as is shown in FIG. 10. In FIG. 10, a ultrasonic transducer is divided into four pieces 106 a, 106 b, —, which are placed on a box type holding means 105 provided around a cutting or grinding rod 101.

FIGS. 11 and 12 illustrate an example of the grinding rod 111 having a grind stone 111 b at the bottom (front end) and an extended portion 111 c. Four ultrasonic transducers 116 are placed on the extended portion 111 c.

FIG. 13 indicates a cutting rod 141 having a pair of cutting throw-away tips 141 d at the bottom (front end) and a ultrasonic transducer 146 in the form of ring. The pair of throw-away tips are preferably arranged symmetrically about the rotational axis of the rod 141.

The electric power supply to the ultrasonic transducer on the cutting or grinding rod can be supplied by means of a rotary power transformer, as is shown in FIG. 14. FIG. 14 is essentially the same as FIG. 2, except that the electric power supply system is replaced with a rotary power transformer consisting of an electric power supplying unit 141 and an electric power receiving unit 142 and that the grinding rod is replaced with the grinding unit of FIGS. 6 and 7. 

1. A cutting or grinding machine comprising an exchangeable cutting or grinding rod, a chuck gripping the cutting or grinding rod by a middle portion or rear end thereof, a motor having a rotatable rod, and a transmission rod connecting the chuck and the rotatable rod of the motor, wherein the cutting or grinding rod has a ultrasonic transducer thereon in an area between a front end of the rod and a portion in contact with the chuck.
 2. The cutting or grinding machine of claim 1, wherein the cutting or grinding rod has the ultrasonic transducer therearound in the form of a continuous or divided ring.
 3. The cutting or grinding machine of claim 1, wherein the cutting or grinding rod has a flange on which the ultrasonic transducer in the form of a continuous or divided ring is arranged.
 4. The cutting or grinding machine of claim 1, wherein the cutting or grinding rod is a rod having a grind stone at a front end thereof.
 5. The cutting or grinding machine of claim 1, wherein the cutting or grinding rod is a drill.
 6. The cutting or grinding machine of claim 1, wherein the cutting or grinding rod is an end mill.
 7. The cutting or grinding machine of claim 1, wherein the cutting or grinding rod comprises a holder rod and a throw-away tip attached to the holder rod.
 8. The cutting or grinding machine of claim 7, wherein the ultrasonic transducer is placed on the throwaway tip.
 9. A cutting or grinding rod having a ultrasonic transducer thereon.
 10. The cutting or grinding rod of claim 9, wherein the ultrasonic transducer in the form of a continuous or divided ring is placed around the rod.
 11. The cutting or grinding rod of claim 9, wherein the rod has a grind stone at a front end thereof.
 12. The cutting or grinding rod of claim 9, wherein the cutting or grinding rod is a drill.
 13. The cutting or grinding rod of claim 9, wherein the rod is an end mill.
 14. The cutting or grinding rod of claim 9, wherein the rod comprises a holder rod and a throw-away tip attached to the holder rod.
 15. The cutting or grinding rod of claim 14, wherein the ultrasonic transducer is placed on the throw-away tip. 